The present invention relates to apparatus for transporting and simultaneously treating discrete commodities, such as levers, castings, casings, fittings or the like. More particularly, the invention relates to improvements in apparatus of the type disclosed in my U.S. Pat. No. 3,830,356 granted Aug. 20, 1974.
U.S. Pat. No. 3,830,356 discloses an apparatus wherein discrete commodities are admitted into one end of an elongated channel wherein the commodities advance toward the other end and are simultaneously treated by a liquid medium or by a flowable solid material, such as steel shot. The channel is defined by two or more parallel rollers which are rotated to continuously change the orientation of the commodities during travel from the one toward the other end of the channel. Each roller is provided with a plurality of asymmetrical elastic conveying elements which are inclined in the direction of desired movement of the commodities and can yield in the radial direction of the respective rollers. The distance between the rollers is selected in such a way that the commodities cannot escape therebetween. The conveying elements, which consist of rubber or other elastomeric material, are resistant to the action of washing liquids and to the action of soft blasting agents. However, their resistance to the action of steel shot or the like is low. Therefore, the versatility of the patented apparatus is rather limited; for example, the useful life of such apparatus is short if the commodities must be subjected to the action of one or more liquid washing agents as well as to the action of hard solid particles which are propelled at an elevated speed against the commodities in the channel.
It was further proposed to treat discrete commodities in a conveyor which includes an endless band assembled of steel plates or an endless rubber band. The band defines a channel which is open at one end, at one side and from above. The commodities to be treated are admitted from above into one end of the channel, and the band is driven in a direction to entrain the commodities from the bottom zone of the channel until they fall back into the bottom zone by gravity. In order to remove treated commodities, the direction of movement of the band is reversed so that the commodities are discharged through the open side of the channel. A drawback of such apparatus is that they can only process batches of commodities, i.e., the treatment must be interrupted whenever a freshly treated batch is to be removed from the channel. Moreover, the apparatus must employ a conveyor which defines a channel of large cross-sectional area so as to allow for simultaneous treatment of a substantial number of commodities. Consequently, the commodities which are admitted into the channel and rise with the upwardly moving portion of the band often reach substantial heights before they drop back into the lower portion of the channel. This can result in damage to or destruction of the commodities.